Got a colleague here who is very competitive. If I say that "I've got 90% test coverage", he'd say he's got 95. If I solve something and share it to him, he'd go to the boss and tell that he's the one who solved it. 😳

The second point is not being competitive, that's your colleague being a cunt.

True competition can drive people to improve, stealing other's ideas and taking credit will not drive anything except hatred and resentment

First point: "That sounds suspiciously high to me. You tried running it through a mutation tester to check your tests are actually working?"

Second point: "Hey boss, just wanted to show you this cool thing that I worked on, I so..... what now? What do you mean Bob said he was responsible for that?! Look, here's the commit log - Bob hasn't worked on that feature at all. I'm frankly shocked and disgusted that he's behaving that way. Could you follow this up? It makes me deeply uncomfortable to be working with such a colleague."